x86, ptdump: Add the functionality to dump an arbitrary pagetable
With reusing the ->trampoline_pgd page table for mapping EFI regions in
order to use them after having switched to EFI virtual mode, it is very
useful to be able to dump aforementioned page table in dmesg. This adds
that functionality through the walk_pgd_level() interface which can be
called from somewhere else.
The original functionality of dumping to debugfs remains untouched.
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Tested-by: Toshi Kani <toshi.kani@hp.com>
Signed-off-by: Matt Fleming <matt.fleming@intel.com>
diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h
index 5ad38ad..938ef1d 100644
--- a/arch/x86/include/asm/pgtable.h
+++ b/arch/x86/include/asm/pgtable.h
@@ -15,9 +15,10 @@
: (prot))
#ifndef __ASSEMBLY__
-
#include <asm/x86_init.h>
+void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd);
+
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
diff --git a/arch/x86/mm/dump_pagetables.c b/arch/x86/mm/dump_pagetables.c
index 0002a3a..20621d7 100644
--- a/arch/x86/mm/dump_pagetables.c
+++ b/arch/x86/mm/dump_pagetables.c
@@ -30,6 +30,7 @@
unsigned long start_address;
unsigned long current_address;
const struct addr_marker *marker;
+ bool to_dmesg;
};
struct addr_marker {
@@ -88,10 +89,28 @@
#define PUD_LEVEL_MULT (PTRS_PER_PMD * PMD_LEVEL_MULT)
#define PGD_LEVEL_MULT (PTRS_PER_PUD * PUD_LEVEL_MULT)
+#define pt_dump_seq_printf(m, to_dmesg, fmt, args...) \
+({ \
+ if (to_dmesg) \
+ printk(KERN_INFO fmt, ##args); \
+ else \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+})
+
+#define pt_dump_cont_printf(m, to_dmesg, fmt, args...) \
+({ \
+ if (to_dmesg) \
+ printk(KERN_CONT fmt, ##args); \
+ else \
+ if (m) \
+ seq_printf(m, fmt, ##args); \
+})
+
/*
* Print a readable form of a pgprot_t to the seq_file
*/
-static void printk_prot(struct seq_file *m, pgprot_t prot, int level)
+static void printk_prot(struct seq_file *m, pgprot_t prot, int level, bool dmsg)
{
pgprotval_t pr = pgprot_val(prot);
static const char * const level_name[] =
@@ -99,47 +118,47 @@
if (!pgprot_val(prot)) {
/* Not present */
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
} else {
if (pr & _PAGE_USER)
- seq_printf(m, "USR ");
+ pt_dump_cont_printf(m, dmsg, "USR ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
if (pr & _PAGE_RW)
- seq_printf(m, "RW ");
+ pt_dump_cont_printf(m, dmsg, "RW ");
else
- seq_printf(m, "ro ");
+ pt_dump_cont_printf(m, dmsg, "ro ");
if (pr & _PAGE_PWT)
- seq_printf(m, "PWT ");
+ pt_dump_cont_printf(m, dmsg, "PWT ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
if (pr & _PAGE_PCD)
- seq_printf(m, "PCD ");
+ pt_dump_cont_printf(m, dmsg, "PCD ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
/* Bit 9 has a different meaning on level 3 vs 4 */
if (level <= 3) {
if (pr & _PAGE_PSE)
- seq_printf(m, "PSE ");
+ pt_dump_cont_printf(m, dmsg, "PSE ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
} else {
if (pr & _PAGE_PAT)
- seq_printf(m, "pat ");
+ pt_dump_cont_printf(m, dmsg, "pat ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
}
if (pr & _PAGE_GLOBAL)
- seq_printf(m, "GLB ");
+ pt_dump_cont_printf(m, dmsg, "GLB ");
else
- seq_printf(m, " ");
+ pt_dump_cont_printf(m, dmsg, " ");
if (pr & _PAGE_NX)
- seq_printf(m, "NX ");
+ pt_dump_cont_printf(m, dmsg, "NX ");
else
- seq_printf(m, "x ");
+ pt_dump_cont_printf(m, dmsg, "x ");
}
- seq_printf(m, "%s\n", level_name[level]);
+ pt_dump_cont_printf(m, dmsg, "%s\n", level_name[level]);
}
/*
@@ -178,7 +197,8 @@
st->current_prot = new_prot;
st->level = level;
st->marker = address_markers;
- seq_printf(m, "---[ %s ]---\n", st->marker->name);
+ pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
+ st->marker->name);
} else if (prot != cur || level != st->level ||
st->current_address >= st->marker[1].start_address) {
const char *unit = units;
@@ -188,17 +208,17 @@
/*
* Now print the actual finished series
*/
- seq_printf(m, "0x%0*lx-0x%0*lx ",
- width, st->start_address,
- width, st->current_address);
+ pt_dump_seq_printf(m, st->to_dmesg, "0x%0*lx-0x%0*lx ",
+ width, st->start_address,
+ width, st->current_address);
delta = (st->current_address - st->start_address) >> 10;
while (!(delta & 1023) && unit[1]) {
delta >>= 10;
unit++;
}
- seq_printf(m, "%9lu%c ", delta, *unit);
- printk_prot(m, st->current_prot, st->level);
+ pt_dump_cont_printf(m, st->to_dmesg, "%9lu%c ", delta, *unit);
+ printk_prot(m, st->current_prot, st->level, st->to_dmesg);
/*
* We print markers for special areas of address space,
@@ -207,7 +227,8 @@
*/
if (st->current_address >= st->marker[1].start_address) {
st->marker++;
- seq_printf(m, "---[ %s ]---\n", st->marker->name);
+ pt_dump_seq_printf(m, st->to_dmesg, "---[ %s ]---\n",
+ st->marker->name);
}
st->start_address = st->current_address;
@@ -296,7 +317,7 @@
#define pgd_none(a) pud_none(__pud(pgd_val(a)))
#endif
-static void walk_pgd_level(struct seq_file *m)
+void ptdump_walk_pgd_level(struct seq_file *m, pgd_t *pgd)
{
#ifdef CONFIG_X86_64
pgd_t *start = (pgd_t *) &init_level4_pgt;
@@ -304,9 +325,12 @@
pgd_t *start = swapper_pg_dir;
#endif
int i;
- struct pg_state st;
+ struct pg_state st = {};
- memset(&st, 0, sizeof(st));
+ if (pgd) {
+ start = pgd;
+ st.to_dmesg = true;
+ }
for (i = 0; i < PTRS_PER_PGD; i++) {
st.current_address = normalize_addr(i * PGD_LEVEL_MULT);
@@ -331,7 +355,7 @@
static int ptdump_show(struct seq_file *m, void *v)
{
- walk_pgd_level(m);
+ ptdump_walk_pgd_level(m, NULL);
return 0;
}